In this study, we investigated the effect of cryptic prophage regions in a bla_NDM-1-bearing plasmid, which was identified in a patient from South Korea, on the survival of bacteria against adverse environmental conditions. First, we conjugated the intact plasmid and plasmids with deleted cryptic prophages into Escherichia coli DH5α. The E. coli transconjugants carrying the plasmid with intact cryptic prophages showed increased survival during treatment with a high concentration of NaCl, high and low temperatures, an oxidative stressor (H₂O₂), and an immunological stressor (human serum). By contrast, the transconjugants carrying the plasmid with a single-cryptic prophage knockout did not show any change in survival rates. mRNA expression analyses revealed that the genes encoding sigma factor proteins were highly upregulated by the tested stressors and affected the expression of various proteins (antioxidant, cell osmosis-related, heat shock, cold shock, and universal stress proteins) associated with the specific defense against each stress. These findings indicate that a bacterial strain carrying a plasmid with intact carbapenemase gene and cryptic prophage regions exhibited an increased resistance against simulated environmental stresses, and cryptic prophages in the plasmid might contribute to this enhanced stress resistance. Our study indicated that the coselection of antibiotic resistance and resistance to other stresses may help bacteria to increase survival rates against adverse environments and disseminate.

中文翻译：

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携带 blaNDM-1 的质粒中的隐蔽预噬菌体可增加细菌在高 NaCl 浓度、高温和低温以及氧化和免疫应激源下的存活率。

在这项研究中，我们研究了在一名韩国患者身上发现的携带bla _NDM-1的质粒中隐蔽的前噬菌体区域对细菌在不利环境条件下存活的影响。首先，我们将完整的质粒和带有删除的隐性噬菌体的质粒结合到大肠杆菌DH5α 中。携带具有完整隐蔽前噬菌体的质粒的大肠杆菌转导结合体在高浓度 NaCl、高温和低温、氧化应激源 (H ₂ O ₂) 和免疫应激源（人血清）。相比之下，携带具有单隐蔽前噬菌体敲除质粒的转接合子在存活率方面没有任何变化。mRNA 表达分析表明，编码 sigma 因子蛋白的基因被测试的应激源高度上调，并影响与特定防御相关的各种蛋白质（抗氧化剂、细胞渗透相关、热休克、冷休克和通用应激蛋白）的表达每个压力。这些发现表明，携带具有完整碳青霉烯酶基因和隐蔽前噬菌体区域的质粒的细菌菌株对模拟环境胁迫表现出更高的抵抗力，并且质粒中的隐蔽前噬菌体可能有助于增强抗逆性。